I seem to be having issues with a Monochron similar to some previously posted. It passes the initial power supply and no-display "beep" tests. The clock boots, can be set, runs for a while (minutes to overnight), then the display freezes/freaks out. I can reset it by pulling and replacing the power. Alarm & 12/24hr settings are preserved on restart, time and date are not (implying an RTC issue?). Testing the coin cell gives 3.3V so I can rule that out. I'm tempted to wipe down the board to remove flux & remelt joints near the RTC.

If need be, I'll post better photos later; the phone camera seems to want to make everything smudgy and washed-out.

Monochron - front

monochron_front.png (409.19 KiB) Viewed 802 times

Yes, C2 should be lying flat. Also, that's a replacement LED for similar reasons. :/

Just noticed R10 is missing (confessional debugging); will investigate the significance of that ASAP.

Monochron - back

monochron_back.png (388.65 KiB) Viewed 802 times

Thanks much,

-- Bob

PS: This is not my week; software issues drove me to hardware. I expect the clock problems to be minor setbacks, though it's part of a long string of failure. Most upsetting was the build process for the IoT Printer kit, but that's a subject for another post (short answer: soldering wire to header pins is a hack, a particularly miserable and frustrating one to spring on someone building a kit. Zero fun.)

R10 is not used, so don't worry about that. Can't really see much detail in the soldering. If you can get some better photos, that would help. A little larger would be good too. About 800x600 should be fine.

I have heard of crystal oscillators misbehaving due to residual carbonized solder flux, but yours doesn't look all that bad from what I can see from here.